The prior art is replete with exercise machines and devices which provide motion resistance to various muscle groups of the human body. These devices vary significantly in force and motion characteristics and are designed to interface with the operator to target specific muscle groups. The general categories of prior art exercise machines or mechanisms include cycles, treadmills, stepping, skiing and rowing machines.
The present invention is a novel mechanism which may be utilized to exercise the upper and/or lower body, and may be described as having a continuous reciprocating type of resistive motion with momentum characteristics of a connected flywheel.
This mechanism is designed to interact with a seated operator. The invention consists of several members which cooperate together to produce an output with force and motion path characteristics which interface with the operator in a new and novel manner. In the simplest embodiment, these members comprise hand or foot motion bar receiving elements connected to a motion bar, where the motion bar is rotatably connected to a flywheel and is caused to pivot at a motion bar trunnion region.
The flywheel is rotatably secured to the machine frame about a flywheel base joint, and is eccentrically connected to the motion bar at a flywheel motion bar first joint. The centerline distance between the two flywheel joints will be referred to in this text as the flywheel eccentric radius. Different force characteristics may be achieved dependent upon whether the flywheel concentrically rotates about an axis fixed to the machine frame, concentrically rotates about the motion bar first joint, or eccentrically rotates about both of the flywheel joints. In the latter case, if the flywheel centroid is purposely located a considerable distance at a particular orientation from either flywheel joint, the momentum characteristics transferred to the motion bar may be timed to be in synch with the maximum efficiency or ability of the operator to react to them, albeit subjecting the machine to additional imbalance and vibration.
The purpose of the trunnion region is to constrain a region of the motion bar trunnion region such that as the motion bar first joint circumferentially travels about the flywheel base joint, the trunnion region is permitted to travel back and forth in a first general direction and not allowed to translate in a generally perpendicular direction. The effect of constraining the trunnion region in one general direction results in a motion path, at the end of the motion bar opposite the motion bar first joint, to travel about a closed curve with a minor axis of a length approximate to twice the length of the eccentric flywheel radius, and a major axis which may be calculated by an equation beyond the scope of this specification.
The motion bar interface region is that portion of the motion bar which directly or indirectly interfaces with the machine operator. During direct interface, the operators feet or hands will cyclically actuate the motion bar during the exercise session, and during indirect operator interface region of the motion bar will be linked to one or more bars or rigid members.
In the embodiments in which the operators feet directly actuate the motion bar, a cross member may extend perpendicularly and laterally out of each side of the motion bar at the motion bar interface region to provide a support for right and left foot placement. In the embodiments in which the operators hands directly actuate the motion bar, the attached cross member would accommodate the operators right and left hand.
The most practical configuration which allows both upper and lower body exercise is to actuate the motion bar directly with the operators feet, and indirectly with the operators hands. When indirectly actuating the motion bar with the operators hands, one or more rigid members are connected to the motion bar at a joint generally between the motion bar foot interface region and the motion bar trunnion region. These rigid members are to be established such that the range of motion of the indirect hand force receiving member operates within the natural hand motion range of the operator. In what may be the preferred operating mode, the operator is to be seated and will alternatingly push with his/her feet until the foot receiving members are at their furthermost forward position, followed by pushing the hand receiving member in order to return the foot receiving member back toward the operator in preparation for cycle repetition. In all of the embodiments shown, the operator may effect flywheel motion by either pushing or pulling the indirect hand receiving member, but the inventor suggests that in order to reduce back strain as is a common problem on mechanisms such as rowing machines, that the hand receiving member be limited to pushing action.
If it is desired to provide means for the operator to exercise each leg in an alternating manner from right to left, a pair of motion bars may be provided and connected to the flywheel at diametrically opposite positions with respect to the flywheel base joint. In this case, each of the motion bars would have its own foot receiving member or foot platform which may move cyclically out of phase one half of a cycle relative to each other. A hand receiving member may also be connected to each motion bar to provide upper body exercise in an alternating side to side manner.
The hand receiving member may be rotatable about an intermediate joint connected to the machine frame and also jointed at a distal end to a coupler member, with the coupler member jointed at opposite coupler member ends to the motion bar and the hand receiving member. The resulting motion to which the grasped hand would be subjected to is a portion of a circular arc which oscillates back and forth during the cyclic action. As previously indicated, during the preferred action, the operators hand(s) will retract while the operators foot (feet) push forward; and while the operators hand(s) push, the operators foot (feet) will simultaneously retract.
Different configurations are possible with the hand receiving member, for example it may be alternatively connected directly to the motion bar, with a linear bearing in proximity to the hands. With this arrangement, as the motion bar(s) move forward away from the operator, the hand receiving member will move forward also. This action would require the operator to pull the hand receiving member as the feet retract.
In discussing the trunnion region, the reader will recognize that the purpose of the trunnion is to act as a pivot point as the motion bar first joint travels along a circumference defined about the flywheel rotational base joint. The flywheel base joint is fixed to the machine frame and as such will cause the motion bar to be levered back and forth upon leveraging interaction between the trunnion region and motion bar first joint as the flywheel rotates. The trunnion region may consist of a trunnion cam connecting the motion bar trunnion region to the machine frame, or a trunnion joint connecting the motion bar trunnion region to the machine frame. Most of the figures illustrated incorporate a trunnion joint, but the reader will realize a joint is only but one means to accomplish this.
The trunnion joint is established in a number of manners, with the primary intention being to act as a motion bar fulcrum. In the examples illustrated, this results in the trunnion region of the motion bar being primarily constrained in a horizontal, machine longitudinal direction. Because vertical action of the trunnion joint is desired in order to prevent the machine from locking up, the trunnion joint may be connected to a distal end of a rocker bar, with the opposite end of the rocker bar connected to the machine frame. This rocker bar is orientated relatively horizontally in order to establish a reaction force at the trunnion which will prevent the trunnion joint from moving horizontally. The actual motion path to which the trunnion joint will be subjected to when supported by a rocker bar is of course arcuate in form.
In an alternative embodiment, the trunnion element (cam or joint) may simply be constrained within a vertical slot machined into a portion of the machine frame. This will allow the trunnion element to move up and down within the slot, but will prevent the trunnion element from moving horizontally in order to cause the motion bar to oscillate. The exact shape of the output path of the motion bar may also be adjusted by establishing a nonlinear or curved trunnion slot. It should be noted that it is arbitrary as to whether the trunnion element is fixed to the machine frame and operates within a trunnion slot incorporated into the motion bar, or whether the trunnion element is fixed to the motion bar and operates within a trunnion slot incorporated into the machine frame.
Discussing now additional operational characteristics of the machine, the reader will realize that the machine would function with an eccentric bar substituted for the eccentric radius of the above described flywheel. Without a flywheel however, lack of inertial properties during motion bar movement would make operation of this machine difficult. The inertial properties contributed by the flywheel assist the operator during brief ranges of motion within each cycle which are inefficient to actuate.
If an eccentric crank is incorporated in place of the eccentric flywheel radius referred to above, and inertial properties are to be incorporated into the mechanism, the flywheel may be located remote. When establishing a remote flywheel, advantages regarding machine weight distribution and operator visibility may be achieved by locating the flywheel close to the machine base. The drive means provided to the flywheel may be nonsynchronous because the machine designer is only concerned with providing momentum to the motion bars, and drive belt slippage is of no consequence. Typical nonsynchronous drive members would consist of flat or V belts. A remote flywheel is illustrated in one of the figures with a synchronous drive member for considerations primarily due to reduction of noise level during machine operation. It has been the inventors experience that typical drive mechanisms, such as those utilized on bicycle machines and the like, produce significant and unacceptable noise levels during maximum cycle speed, particularly at the extremely high cycle rate during prolonged sessions that the inventor subjects them to.
Continuing now with additional dynamic considerations of this machine, mechanical components such as springs and linear or rotational dampers will now be discussed.
First, in reference to springs, a compression spring may be connected between the motion bar and the machine frame in order to bias the motion bar rearward toward the operator. A spring may also be incorporated on embodiments which do not allow indirect motion bar actuation with the operators hands.
The motion bar may alternatively, or supplementarily, be restricted by a linear damper fixed to the machine frame. Properties of linear dampers include resistance adjustability and damping functionality in one or two directions. Generally, when linear dampers are employed, the primary intention is to add resistance to the motion bar while the motion bar is being pushed by the operators feet.
The flywheel may alternatively or supplementary be dampened by an adjustable rotational damper in order to introduce friction into the system. Such dampers typically consist of a band brake which frictionally engages with the outer circumference of a flywheel, although rotational damping action could also be created with hydraulic means, or the use of electromechanical components when utilizing eddy currents and the like.
Although this invention does not rely upon six bars in all design versions, the reader will note six bars are present in the first embodiment shown in FIG. 1. These bars are the hand receiving member, coupler member, motion bar, rocker bar, flywheel, and the machine frame.
Based upon kinematic analysis, and omitting all input from the operators upper body, accurate values for the motion bar/rocker bar/flywheel configuration shown in the first embodiment during successful machine cycling are as follows: Flywheel weight 20 pounds (89 N), flywheel rotational damper torque 0.07 lb-in-s/degree (0.45 N-m-s/radian), flywheel average rotational velocity 50 rpm (5.2 radian/sec), flywheel eccentric radius 0.61 in (16 mm), distance between trunnion joint axis and motion bar first joint axis 1.80 inches (46 mm) where motion bar first joint is orientated at the six o""clock position with respect to the flywheel rotational axis, foot receiving element input force at 25 pounds (111 N) occurring during one half machine cycle, and approximate foot receiving element displacement 14 inches (0.35 m).
If the operator supplementarily exerts force of 15 pounds (67 N) at the hand receiving member element during the foot receiving element back stroke, the flywheel rotational damper may be increased to 0.11 lb-in-s/degree (0.71 N-m-s/radian) while maintaining the same average flywheel rotational velocity of 50 rpm (5.2 radian/sec). The reader may note that these computations represent a general example, and excludes considerations of one or two way linear dampers, air springs, compression or tension wire form springs, or any other force resisting means which may be installed to act upon any of the moving rigid members.